July 5, 2018 -- Deodorant, shaving cream, toothpaste, trash cans, clothing, cutting boards, credit cards: These are just a few of the ways consumers can come into contact with triclosan. A growing body of evidence suggests that it can be harmful. Should you be concerned?
Triclosan, an antibacterial and antimicrobial chemical, has been used in personal care products and as a pesticide for decades. Scientists in recent years have stepped up their research into its potential health risks, says University of Maine biochemist Julie Gosse, PhD.
Gosse has published studies on triclosan’s effects on mitochondria -- cell components that play a role in human reproduction and other functions. “We know that it harms mitochondria, and we know that mitochondria function is essential for reproduction, and we know that triclosan affects reproduction,” she says.
But the research has been conflicting. A 2013 review of 30 studies looking at the use of triclosan in toothpaste, for example found it was safe.
“There do not appear to be any serious safety concerns regarding the use of triclosan/copolymer toothpastes in studies up to 3 years in duration,” the authors of what’s known as the Cochrane Review wrote.
The EPA, which has authority over its use in products such as toys and textiles, assessed triclosan in 2008 to find out if it harms human health. It found nothing of concern.
The FDA banned the chemical’s use in antibacterial liquid soaps in 2016. It did the same last year for over-the-counter antiseptic products, such as hand washes and surgical scrubs, in hospitals, doctors’ offices, and other health care settings. The agency banned it from antibacterial soaps because, it said, companies failed to prove triclosan was safe.
The FDA’s ban was limited, in part, because of the way products are regulated. Soaps that make antibacterial claims are considered over-the-counter drugs and subject to FDA approval. But the agency has different regulatory power over products considered cosmetics, such as shaving gels and lotions, in which triclosan may be used as a preservative. These products don’t have to gain FDA approval before being sold.
While some major manufacturers went further than the FDA bans required, a recent study says 2,000 or more products are thought to contain triclosan, and it is also found in the environment. Another study estimated that 96% of triclosan was used in products that end up down the drain, such as soaps and detergents.
“Because of its use in so many products, it enters the environment, it enters the sewage system,” says Ted Schettler, MD, science director for the Science and Environment Health Network in Eugene, OR. “Triclosan has been detected in fresh water streams and rivers all over the country. … It’s been measured in fish that we eat and in vegetables, so we can get it indirectly as it moves through.”
Research on Triclosan
So how much do consumers need to worry?
In a statement announcing the ban in antibacterial soaps, the FDA said manufacturers had not proved its safety or shown it offered better protection than soap and water. “Some data suggests that antibacterial ingredients may do more harm than good over the long-term.” Potential health risks the agency cited were bacterial resistance and “hormonal effects.”
And a great deal of the research on the potential health impact of triclosan, including that done by Gosse, has been done on rodents and other animals. Few human studies have been done.
Schettler says that while we need more human data, it is important to look at animal studies. “We use animal studies all the time for predicting the effects of chemicals in people,” he says.
Schettler was one of more than 200 scientists and medical professionals to sign the Florence Statement on Triclosan and Triclocarbon published in 2017. It outlines what the group considers the major health concerns about triclosan. (Triclocarbon does many of the same things as triclosan but is used in different products.) These concerns include triclosan’s potential impact on:
Human reproduction and development. Animal studies have linked triclosan to lower testosterone levels and less sperm production. It also may affect the thyroid, which produces hormones essential to brain development in children. There’s too little human research to say whether triclosan would affect people in a similar way.
Allergies and asthma. Animal and human studies suggest that triclosan may make people more sensitive to allergens. That doesn’t mean triclosan causes hay fever, for example, but it may cause hay fever symptoms to be triggered by a smaller-than-usual amount of pollen. It’s also been linked to worsening asthma among people who already have the condition. “Triclosan may contribute to the rise in allergies and asthma that we’re seeing,” Schettler says
Antibiotic and antimicrobial resistance. Some research suggests that bacteria may become immune to triclosan over time. That may make it and other antimicrobials less effective. Schettler says it’s too soon to tell what, if any, impact that may have on antibiotic resistance, but “it’s a real concern.”
Gut bacteria: A study published in May focused on triclosan in one particular type of product: toothpaste. In the study, led by Guodong Zhang, PhD, an assistant professor of food science at the University of Massachusetts
Amherst, researchers fed mice a solution that contained triclosan in amounts they say are comparable to what you’d absorb when you brush your teeth. They found that it altered the mice’s gut bacteria. After 3 weeks, some of those mice had gut problems, including inflammation of the colon. In mice bred to get colon cancer, those fed triclosan developed more and larger tumors.
This study has “limited relevance for human health,” says Brian Slezak, PhD.
Slezak is a toxicologist at Colgate-Palmolive, makers of Colgate Total toothpaste, the only toothpaste that still contains triclosan.
The research has a “fundamental flaw” because “mice metabolize triclosan far differently than humans,” he says. “The majority of the findings were observed at levels 1,900 times higher than exposure from brushing” teeth with Colgate Total, he says.
The FDA says Colgate Total is a safe and effective means of preventing gingivitis, a mild type of gum disease. Slezak cites Colgate-Palmolive’s own research over the past 20 years, which includes 90 clinical studies and 20,000 subjects, as well as the FDA’s stamp of approval.
“Based on the body of research, consumers can be confident in the safety and efficacy of this ingredient as used in Colgate Total toothpaste,” he says.
Gastroenterologist Eugene Chang, MD, who was not involved in Zhang’s study, agrees that mice are a far from perfect stand-in for humans, but he says the results do raise concerns.
“Upsetting the [gut] microbiome early in life can have lasting consequences,” says Chang, a professor of medicine at the University of Chicago and board member of the American Gastroenterological Association’s Center for Gut Microbiome Research & Education.
For example, he says, the microbes in your gut influence your immune system’s development. Something that upsets those microbes, such as a chemical like triclosan, might “distort the way your immune system develops.”
Checking Products for Triclosan
Gosse advises caution in using the chemical until more is known.
“We want to be careful, and as consumers, we want to know as much about it as we can,” she says.
Personal products that contain triclosan must mention that fact on the label. A number of manufacturers of these products have removed or are taking steps to remove the chemical from some or all of their products.
Procter & Gamble has removed triclosan from all of its products. Johnson & Johnson no longer uses it in its baby, cosmetic, and personal care products. Unilever has pledged to remove triclosan from all its products by the end of this year. On its website, Unilever cites consumer preference as the reason for the removal. The company considers triclosan to be safe.
Yet many products that are not for personal care get exemptions that allow their manufacturers to market their products without noting the use of triclosan or other pesticides, says Mae Wu, senior attorney of the National Resources Defense Council Health Program. The organization filed the lawsuit that led to triclosan’s ban in antibacterial soaps.
Wu says consumers can look for clues. If something is marketed with terms such as ‘antibacterial,’ ‘fights odors,’ or ‘fights germs,’ triclosan may be present. “The onus is on the consumer to determine if it’s being used,” she says. That could mean contacting the manufacturer to ask.
“We know that some major companies were out ahead of this ban and getting it out of their products,” says Samara Geller, a senior researcher and database analyst at the D.C.-based Environmental Working Group. “But it’s just so widespread.”
The Environmental Working Group’s website has a database of personal care products that consumers can search to learn if anything that they use or are considering using contains triclosan. Though the database includes more than 70,000 products, it is not comprehensive, and you may not find listings for the products that concern you. Also, some products found on the list may have been discontinued or been remade with different ingredients. Currently, the database includes 47 products that contain triclosan. The list does include some products that fall under the ban. That’s because they may still be on store shelves or in your home.
The EPA is now working on an updated risk assessment that all pesticides get every 15 years. According to the agency, the final report is expected in 2019.